Which constitutional amendment protects against improper exercise of personal jurisdiction?

The correct answer is the Fourteenth Amendment. This amendment is crucial in the context of personal jurisdiction because it includes the Due Process Clause, which establishes the principle that a legal judgment against an individual or entity is valid only if the court has proper jurisdiction over that individual or entity.

Specifically, the Due Process Clause ensures that defendants are not subjected to the jurisdiction of a court in a state where they have insufficient contacts, ties, or relations. This means that a state must have a significant connection to the individual or the case at hand for its courts to exercise jurisdiction. The Fourteenth Amendment protects individuals from the arbitrary exercise of power by the state and ensures fairness in legal proceedings.

Other amendments listed do not pertain specifically to the principles of personal jurisdiction. For instance, the Eighth Amendment deals with excessive bail, fines, and cruel and unusual punishments, while the First Amendment focuses on freedoms concerning religion, expression, assembly, and the right to petition. The Fifth Amendment addresses rights in criminal cases, including due process concerning federal actions. Therefore, the Fourteenth Amendment is the definitive protector regarding issues of personal jurisdiction in a state court context.